You might try different size mouse say like a just weaned size, My Ball from Petco would be dead now If I followed PetCo instructions, if it need be you may have to try live Mice to get her going this is just my opinion. .... I have seen PetCo starve babies to death by following Corporate Rules Pretty Sad. Keep us posted on all the weight issue's , you might want to buy a digital scales from like Staples, Walmart,, etc.

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